A new semi-active suspension control strategy through mixed H_2/H_∞ robust technique

A new semi-active suspension control strategy through mixed H2/H∞ robust technique was developed due to its flexibility and robustness to model uncertainties.A full car model with seven degrees of freedom was established to demonstrate the effectiveness of the new control approach.Magneto-rheological(MR) dampers were designed,manufactured and characterized as available semi-active actuators in the developed semi-active suspension system.The four independent mixed H2/H∞ controllers were devised in order to perform a distributed semi-active control system in the vehicle by which the response velocity and reliability can be improved significantly.The performance of the proposed new approach was investigated in time and frequency domains.A good balance between vehicle's comfort and road holding was achieved.An effective and practical control strategy for semi-active suspension system was thus obtained.This new approach exhibits some advantages in implementation,performance flexibility and robustness compared to existing methods.

Mixed H_2/H_∞ State Feedback Attitude Control of Microsatellite Based on Extended LMI Method

For the appearance of the additive perturbation of controller gain when the controller parameter has minute adjustment at the initial running stage of system,to avoid the adverse effects,this paper investigates the mixed H_2/H_∞ state feedback attitude control problem of microsatellite based on extended LMI method.Firstly,the microsatellite attitude control system is established and transformed into corresponding state space form.Then,without the equivalence restriction of the two Lyapunov variables of H_2 and H∞performance,this paper introduces additional variables to design the mixed H_2/H_∞ control method based on LMI which can also reduce the conservatives.Finally,numerical simulations are analyzed to show that the proposed method can make the satellite stable within 20 s whether there is additive perturbation of the controller gain or not.The comparative analysis of the simulation results between extended LMI method and traditional LMI method also demonstrates the effectiveness and feasibility of the proposed method in this paper.

Designing mixed <i>H</i>₂/<i>H</i>_&infin;structure specified controllers using Particle Swarm Optimization (PSO) algorithm

This paper proposes an efficient method for designing accurate structure-specified mixed H2/H∞ optimal controllers for systems with uncertainties and disturbance using particle swarm (PSO) algorithm. It is designed to find a suitable controller that minimizes the performance index of error signal subject to an unequal constraint on the norm of the closed-loop system. Although the mixed H2/H∞ for the output feedback approach control is considered as a robust and optimal control technique, the design process normally comes up with a complex and non-convex optimization problem, which is difficult to solve by the conventional optimization methods. The PSO can efficiently solve design problems of multi-input-multi-output (MIMO) optimal control systems, which is very suitable for practical engineering designs. It is used to search for parameters of a structure-specified controller, which satisfies mixed performance index. The simulation and experimental results show high feasibility, robustness and practical value compared with the conventional proportional-integral-derivative (PID) and proportional-Integral (PI) controller, and the proposed algorithm is also more efficient compared with the genetic algorithm (GA).

汽车四轮转向系统的H_2/H_∞混合控制

为使汽车四轮转向系统具有良好的鲁棒性和干扰抑制性能 ,针对外界干扰 ,对汽车四轮转向系统模型进行了分析 ,并将其转化为H2 /H∞ 控制问题 ,运用Matlab的LMI控制工具箱设计了H2 /H∞ 混合最优控制器。仿真结果表明 ,设计的最优控制器具有良好控制效果。

H_2/H_∞保性能控制理论在静止无功发生器控制中的应用

利用H2/H∞保性能控制理论和直接反馈线性化,给出了单机无穷大系统中,具有参数摄动的静止无功发生器(STATCOM)的非线性控制模型.使用MATLAB软件得出H2/H∞保性能控制律,表示为线性矩阵不等式(LMI).在扰动及参数摄动的条件下进行了仿真.结果表明这种控制方法同时具有鲁棒性和最优性能,降低了单纯H∞控制方法的保守性,提高了电力系统的稳定性,并满足电压精度的要求.

On the Dual of a Mixed H_2/l_1 Optimisation Problem

The general discrete-time Single-Input Single-Output （SISO） mixed H2/l1 control problem is considered in this paper. It is found that the existing results of duality theory cannot be directly applied to this infinite dimension optimisation problem. By means of two finite dimension approximate problems, to which duality theory can be applied, the dual of the mixed H2/l1 control problem is verified to be the limit of the duals of these two approximate problems.

建筑结构振动主动控制的H_2/H_∞混合凸优化方案

在地震信号和建筑结构系统的范数分析基础上,使用了混合控制优化指标J作为优化目标,并给出其物理含义·针对H2控制方案和H∞控制方案的优缺点,通过LMI凸优化方法求解混合控制器,给出了在给定γ值的前提下极小化指标J的H2/H∞混合控制方案,并给出了仿真算例·

巡航导弹成像器稳定装置H_2/H_∞混合最优PID控制器设计

本文针对某巡航导弹成像器稳定装置同时在鲁棒稳定性和系统性能有着很高要求的特点 ,采用H2 /H∞ 混合优化的设计方法设计了H2 /H∞ 混合最优PID控制器。仿真和实验结果表明采用该设计方法设计的巡航导弹成像器稳定装置满足性能要求 ,而且比采用H∞

固定结构混合H_2/H_∞控制器参数的全局优化

首先运用增广 Hermite- Biehler定理 ,解析地给出使任意给定 (稳定或不稳定 )被控对象闭环稳定的控制器参数取值域 .然后 ,在该参数取值域内运用遗传优化算法得到了满足指定混合 H2 / H∞ 性能指标的 Pareto最优控制器参数值 .仿真例子验证了该方法的有效性 .

静止无功补偿器的H_2/H_∞保性能控制器设计

在H2/H∞保性能控制理论和直接反馈线性化的基础上,文章研究了SVC(静止无功补偿器)的控制器设计,对具有SVC的单机-无穷大系统,建立了含不确定因素的数学模型。采用解LMI(线性矩阵不等式)方法,利用MAT- LAB/LMI工具箱,得出H2/H∞保性能控制律。分析表明这种控制方法兼有鲁棒性能和最优性能,降低了单纯H∞控制方法的保守性,提高了电力系统的稳定性,并能满足电压精度的要求。

励磁系统的H_2/H_∞保性能控制器

基于H2/H∞保性能控制理论和直接反馈线性化研究了单机-无穷大电力系统的励磁控制器设计。建立了含不确定因素的数学模型,采用解线性矩阵不等式(LM I)方法,利用MATLAB/LM I工具箱得出发电机励磁的H2/H∞保性能控制律。分析表明这种控制方法兼有鲁棒性能和最优性能,使H∞控制具有较小的保守性,提高了电力系统的稳定性,并能满足电压精度的要求。

土木工程结构抗震主动控制H_2/H_∞混合优化设计

将地震信号分解为有界集合描述的确定性部分和随机变量数字特征描述的不确定部分 ,在地震信号和结构系统的范数分析基础上 ,使用了混合控制优化指标J作为优化目标 ,并给出其物理含义。针对H2 控制方案和H∞ 控制方案的优缺点 ,给出了在给定γ值的前提下极小化指标J的H2 H∞ 混合控制方案 。

不确定离散时间系统的H_2/H_∞最优保性能控制

针对具有两个不同被调输出的一类不确定离散时间系统 ,研究了其 H2 /H∞ 状态反馈保性能控制问题。基于线性矩阵不等式处理方法 ,导出了存在 H2 /H∞ 保性能控制律的充分必要条件 ,并用一个线性矩阵不等式的可行解给出了所有保性能控制律的一个参数化表示。进而 ,通过建立和求解一个凸化问题 ,给出了 H2 /H∞最优保性能控制设计方法。最后 。

H_2/H_∞组合方法及其对导弹纵向运动的控制分析

在对Ｈ２／Ｈ∞组合控制问题描述和分析的基础上，总结了此类问题的一种求解算法，即转换为双线性矩阵不等式问题，通过迭代运算加以求解。以某型导弹纵向运动的控制为例，对Ｈ２／Ｈ∞组合算法进行了仿真计算，结果表明，该方法在一定程度上协调了系统的Ｈ２及Ｈ∞设计任务间的矛盾，使得所设计控制系统不但有着要求的噪声抑制能力，而且具有良好的鲁棒稳定性。

基于LMI的磁悬浮列车姿态H_∞/H_2混合控制

针对目前新型的单轨磁悬浮列车姿态控制问题 ,建立了磁悬浮列车姿态的状态空间模型 .在对该模型进行线性化后 ,设计了基于 LMI的 H∞ /H2 混合控制器 ,有效地控制了列车运行时发生的车厢上下振动及其倾斜 .通过系统仿真 ,得到此种控制器具有良好的控制性能 .

微制造平台微振动的H_2/H_∞混合控制

基于啄木鸟头部生物构造及其仿生隔振机理 ,采用混合隔振技术建立了微制造平台隔振系统。该系统以空气弹簧和橡胶层作为被动隔振元件、超磁致伸缩致动器作为主动隔振元件。针对 H2 最优控制和 H∞ 鲁棒控制的优缺点 ,主动控制器采用H2 / H∞ 混合控制进行设计 ,并通过 L MI凸优化方法求解 H2 / H∞ 混合控制器。仿真结果表明所设计的 H2 / H∞ 混合控制器具有良好的鲁棒稳定性和时域性能 ,可在非常宽的频率范围对基础干扰和由微制造设备产生的直接干扰所引起的微制造平台振动进行有效的控制 ,其振动控制效果明显优于 H∞

遗传算法在混合H_2/H_∞优化控制设计中的应用

介绍了现已成为关键智能计算之一的一种新的全局优化搜索算法—遗传算法，并探讨了在混合Ｈ２／Ｈ∞最优指标下优化控制设计中的应用。其最大特点是：本质并行、全局优化，它不要求目标函数连续和可微，比梯度法和随机搜索算法更适合于ＰＩＤ混合Ｈ２／Ｈ∞优化问题。

地震作用下结构振动保性能鲁棒H_2/H_∞控制

针对建筑结构振动控制模型的不确定性,研究了被控建筑结构模型参数不确定性时的保性能鲁棒混合H2/H∞控制问题。将结构模型参数不确定性引入到被控结构状态方程的摄动矩阵之中,基于线性矩阵不等式设计了多目标保性能鲁棒混合H2/H∞鲁棒控制器。该控制器在规定的模型参数变化范围内,使得闭环控制系统同时满足H∞干扰抑制和最优H2性能。最后,以一个缩尺的多层剪切型建筑结构模型为例,给出了保性能鲁棒混合H2/H∞控制问题的设计过程,验证所提控制方法的有效性。数值分析结果表明,所提出的保性能鲁棒混合H2/H∞控制方法的控制效果明显,能有效地减小结构的地震峰值响应,且控制系统对结构参数不确定性有很强的鲁棒性。

Three-dimensional nonlinear H_2/H_∞ guidance law based upon approach of solving the state feedback Nash balance point

Based upon the theory of the nonlinear quadric two-person nonzero-sum differential game,the fact that the time-limited mixed H2/H∞ control problem can be turned into the problem of solving the state feedback Nash balance point is mentioned. Upon this,a theorem about the solution of the state feedback control is given,the Lyapunov stabilization of the nonlinear system under this control is proved,too. At the same time,this solution is used to design the nonlinear H2/H∞ guidance law of the relative motion between the missile and the target in three-dimensional(3D) space. By solving two coupled Hamilton-Jacobi partial differential inequalities(HJPDI),a control with more robust stabilities and more robust performances is obtained. With different H∞ performance indexes,the correlative weighting factors of the control are analytically designed. At last,simulations under different robust performance indexes and under different initial conditions and under the cases of intercepting different maneuvering targets are carried out. All results indicate that the designed law is valid.

不确定离散时滞系统具有H_∞干扰抑制的保成本控制

针对一类用矩阵凸多面体形式表示的不确定线性离散时滞系统 ,提出一种通过无记忆状态反馈实现的具有 H∞ 干扰抑制的保成本控制。当对象存在不确定性以及外部干扰统计特性未知时 ,该控制器能保证闭环系统稳定和一定的线性二次型性能指标上界 ,同时具有 H∞ 范数下的干扰抑制作用。基于L yapunov稳定性理论 ,控制器设计可转化为线性矩阵不等式的可解性问题。数值仿真表明 。